Your mix will work fine for tomato plants and if peppers are happy under your fluorescents then the tomatoes should do fine. You will have to continue rooting cuttings all winter to keep them small. You might try keeping a larger plant cut back and let it produce multiple shoots for rooting later.

Wow, interesting idea!

I thought toms and peppers were shot after 1 season.....are they perennial in mild climates?

I know of a couple of plants that were kept alive almost 2 years inside. They eventually got root bound and too big to transplant and cuttings were taken from them. They lived on to produce but not sure how long as I lost touch with the person growing them. AFAIK peppers are the same way.

Last year I had one jalapeno I didn't plant out. Brought it in and put it in the garden window where it produced one pepper in Sept. Because the plant was still green I kept it and watered occasionally. This April, it produced a few tiny peppers. I was stunned because I thought they were annuals, but apparently can be kept going for at least a year.