YOu need something with a sickle bar.

For may years my Grandfather maintained a property like this (I think about half of the 8 acres was woods and the other half feilds and very rocky steep meadow) with a walk behind 2-wheel gravely and a sickle bar. He'd cut twice a year.

Depending on the slope, something like that might be best, or you may be able to find a 4 wheel tractor with a sickle bar to handle it.

I am sure we will hear more...

Here's this one. http://www.power-trac.com/tsmclass.htm#1850

Pricey too. There is another that I can't think of right now. Articulating, and quite impressive.

Here is a link that might be useful: Power-Trac

Depending on the actual acreage you'll want to mow, a small used Yanmar/Kubota/Massey/JohnDerre sub-compact tractor with a rear, three-point mounted, rough cut rotary mower might serve you well for springtime cutting of pasture land in the foothills. There are numerous dealers in Bakersfield, Fresno, Stockton, Sacramento, and Redding that could find you a reasonable tractor w/mower setup for under $6000 that would last you a lifetime. Get yourself a good strong Stihl weed trimmer with a bicycle handle setup for mowing around the granite out-croppings and slopes too steep for mowing.
Myself? I purchased a Husqvarna 2748GLS for my one acre lot in Tehachapi for $2900 and it took me 3.8 hours to mow my overgrown, gopher/ground squirrel infested lot on the highest deck setting (3.5"). I have a Stihl FS130 for trimming the slopped areas. Next year, I'll mow before the grass gets two feet high so I don't beat the poor Husqvarna to death playing catch-up. Seven acres of similiar land, or even three acres of similiar land would be reason enough for me to shop for a sub-compact tractor with a rough cut mower.

!Remember to flag the sprouting oak trees to avoid mowing them off. They need all of the help they can get to replace the standing ancient oaks that make the California foothills and Sierra valleys unique. They estimate the tree in my front yard (a Oregon White Oak) to be older than Christopher Columbus.

Good luck in your search; autumn and winter is the best time shop for used mowing equipment in California. Watch the Craig listings too.

You may want to consider one of these tow behind "bush hogs", see link below. Seem to be designed for what you describe. If you only have to cut once or twice a year, you might consider renting a 4WD tractor with a bush hog. These go for about $125 a day deliverd in N. Georgia for a Kubota that also comes with a front end loader that might be handy a couple of times a yar.

Here is a link that might be useful: Tow behind trail cutters

I have a Gravely convertible walk behind with the 30" bush hog mower. I can attest that will tolerate mowing rough ground very well as over the years I have hit rocks, stumps, etc, with it multiple times and had no damage. The slip clutch between the mower and the transmission really works. Having said that I would hate to think of mowing 7.5 acres with it. It would take days.

You can mow your ground and grass with Dixie chopper without damage to mower it climb like trail Bike and mulch rocks to dust.

ibmoto hit it dead on if you are cutting any thing near the full 7+ acres. All the Fire Dept. requires is that an area 100 ft around your buildings be mowed. If your property, like mine on Bear Mt., has slopes of over 15 degrees a tractor is not usable. I find it is easier to use a hand held trimmer than the wheeled model. The hand held is lighter and easier to control on the slopes. One other thing, when mowing check your mower deck, belts and pulleys often for dirt and debris build up.

The only rugged terrain mower's and tractors that come to mined are Ventrac and Steiner

Here is a link that might be useful: Steiner

If you decide to go with a tractor-mounted sickle bar, I'm pretty sure they're no longer available for GTs. However, I have seen quite a few (well... three or four over the past year) Haban sickle bars for sale on eBay which are most commonly fit to the old JD 110 or 140 series.

I've used a GT for light bush hogging with the deck fully raised, but as ibmoto stated, you only get about 3-4" of clearance from rocks. I believe the Haban sickle bars will bounce backwards if they hit an obstacle.