Peppers will do fine in 5-gallon buckets. Most tomatoes, other than patio or micro or certain determinates, will do much better in larger containers. I use a 15-gallon for my cherry tomato.

As for the mix, there's not much to say. I wouldn't recommend either of the strategies you mentioned, nor would I recommend either of those mixes.

Josh

Where did you get the 15-gallon? What soil mixture do you recommend?

The 15-gallon came from a local nursery....I can't recall the price, but it wasn't too high. On my back deck, I set the pot in a black plastic tub, the kind you could use for mixing small batches of mortar or concrete. On hot days, I can water until an inch or so fills up in the tub, then let the container suck up the moisture the rest of the day.

I highly favor a bark-based mix, with small fractions of peat/potting mix and perlite, known as the 5-1-1 (5 parts bark, 1 part peat, 1 part perlite). In Texas, you might increase to 2 parts potting mix, if you find the moisture retention insufficient.

Josh