I can only answer two of your questions:

2. I've been very happy with Rosy Dawn, and yes, the sun coleus were all perfectly happy in full sun.

4. My basement is 65 F. and cuttings have been fine.

1)Where can I buy them for best price? I only need like maybe 10 full sun types.

I do like RD...have had wonderful luck with their plants, although some were easier rooted from cuttings than others (I use water cups only for this, so perhaps my success would have been better with some other method)

2)Whats your opinion about Rosy Dawn online? They have Sun coleus - are they really full sun tolerant?

Very good plants. Here is some text from their FAQ page:
Sun or Shade? The amount of light your Coleus plants receive will affect their coloration, so the same variety of Coleus grown in two different locations in your yard may vary in appearance. Most Coleus can take some sun, and several can tolerate full sun if properly acclimated. Coleus grown in full sun will create more pigmentation to protect itself from the sun. For example, bright yellow or chartreuse may become a dark gold or green. Oranges may become red. Reds may become burgundy. Dark colors may dominate lighter colors on the leaf. Results also vary according to region. Full sun for our friends in Texas or Florida is much stronger than full sun for us here in Michigan! The most important thing to remember when growing coleus in full sun is that they need proper preparation and consistent watering to look their best.

Coleus have historically been considered a shade plant, and Coleus do grow well in dappled or partial shade, but no coleus will do well in deep shade. Coleus are not mushrooms and a certain amount of light is necessary to maintain the proper level of pigment in the leaves. The deeper the shade, the more washed out the colors will be. Deep shade may also cause lanky, contorted growth as the plant stretches towards light, and damp soil may cause disease.

The plants that are photographed for the Rosy Dawn Garden catalog are mature plants that have been grown in bright morning light with protection from the afternoon sun.

Which Coleus will take full sun?
A lot of companies have been promoting "sun coleus" and, in fact, many varieties are sun-tolerant. However, "full sun" is a relative, as well as misleading, term. Full sun in Michigan where we live is a whole different thing than full sun in Florida or Texas or Arizona. Another relative term is "grow." Growing or surviving is different than "thriving." Many coleus will survive and grow in full sun but constant exposure to strong sunlight can alter the coloring of the plant and greatly increase the need for water. The best location for the truest color in coleus, in our opinion, is a spot that receives some sun (preferably morning sun) but is protected from the harshest sun of the middle and/or late day. Of course, many people do not have an ideal exposure available in which to grow coleus, so experimentation is certainly in order. Many of our customers have success in full sun. Red, burgundy, deep purple, and medium to dark green varieties generally do well with a lot of sun. Plants with spots, stripes, and variegation along with white, yellow, gold, and chartreuse varieties can become "greened out" and less attractive by the excess coloring produced by the plant to protect itself from the sun. See our Selection Guide page for more information on the varieties of coleus that can tolerate sun.
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3) Rosy gives a free one for each plant - the free one - is it a good contrast or a plain cheap green one?If I buy 3 will I get 3 free?

It depends on the size of your order. As I recall, I ordered about 20 plants the first time and got 2 free. Nope, not a cheap plain green one. I got one called Antique and one called Bi Polar, Bi Golly with my order.
More text:
How many coleus plants do I get for the price?
Our plants are individually priced. Each plant is $4.75. We do not sell wholesale or offer quantity discounts. You will receive one or more bonus plants of our choice depending on the size of your order.size>

4) Whats the min temp for cuttings to over winter- I can only put em in basement which is like 55 to 65 F.

They'll live outside in those temps, so I would venture to guess they'd be fine.

5) Whats the sign that a coleus is not doing great in sun, leaves drooping?browning?Color Loss?

No clue on that one.

Here's another great coleus site that you can check out. I have no information on their reliability, but they sure have a lot of info!

Glasshouse Works
Part 1 Coleus
Part 2 Coleus,