Because you are using this for live use (as opposed to studio use), I would not use a laptop or computer with a VSTi or other soft instrument. You are asking for problems.
I would, instead, get an inexpensive used sound box from Roland, or similar. You could pick up a used roland Fantom Rack, 5080, 3080, 2080, or 1080 and have good Rhoads and piano sounds. You'd hook up the midi out of your keyboard to the midi in of the Roland box. And this would be a bullet proof solution. No blue screens, no driver updates, no computer glitches. It will just work and it will sound good.
Of all of the boxes I listed, at current prices, I think the 3080 is probably the best bang for your buck. You should be able to pick one up for around $300. They support SRX and JV cards. These cards are still available on eBay.
Just my 2 cents.