I like vinyl either tile look or wood look . We have it in our walkout I love it and with 3 huge dogs the best choice IMO. I think if converting it is in athe near furure I would wait until you have designed the new space so you know where to install .

I do not like tile in a basement because it is SUPER COLD. In HOT climates (not even warm....but HOT) this is tolerable/accepted.

If you wish to turn this into a legal (or illegal...your choice) suite, then you will want to think about sound. Carpet is deadening the sound moving between the upstairs and the down stairs. Before you go ahead and pick anything, you will want to take note of how the carpet is deadening the sound right now.

Then pull out the carpet and leave the cement exposed for 2-3 weeks. See how much of a difference a sound deadening property the carpet offers. There are a few things that will recreate that deadening:

1. More carpet

2. Cork floating floor with cork underlayment

3. Laminate with sound deadening underlayment

4. Subfloor system (like Patricia's) like Dricore with vinyl over top

Vinyl does NOT like underpad. That's where it gets tricky to reduce noise with vinyl. Laminate is different, it LOVES a good acoustic underpad.

Just a little bit to think about before you convert the basement to an apartment. You might find you have to update the noise insulation between the floors before you rent it out.