[woolybully]

Everyone's suggesting VR rigs, as you requested, but hold up a sec, he wants to learn to skateboard or rollerblade. While some of the VR rigs may help a person learn such a skill, most are purely "rides", with the person having little or no control. I'd urge you to not be so quick to forgo actual skateboarding, rollerblading, or similar actual, physical activities. He wants the feel of the wind in his face, the feel of balance.

Can he ride a bike? Has he ever, and can he still? How physically strong is he currently? Can he still lift himself out of a chair? If he's not very strong, perhaps you could sit with him on a long board and go down gentle slope, or start on a flat. Maybe take your sisters first and get their approval. A Razor skooter might be a good compromise - very easy to learn, but have the correct wind and the balance components. How much does he weigh? If you outweigh him by a good margin, you could both rollerblade, with him between your arms, and your arms under his, so you can be his training wheels. Again, obviously much caution with everyone's approval before you actually do this.

How 'bout a Big Wheel? If you get on a snow ski slope, there are other options; have you seen these bi-skis where a person sits and a person behind them stands and steers?

Of course, none of these preclude also going the VR route, though budget may. Just wanted to throw out some options possibly more inline with what he may have in mind.