It would have to be a pretty large garden, as the minimum recommended distance between varieites is 500 feet if you want to assure seed purity. But there are ways around that.
The simplest way to grow multiple varieties is to choose one from each of the five domestic species commonly available. While peppers are the sluts of the garden (they'll cross if you even look at them cockeyed), they only crossbreed within a species. So you could grow one each of Casicum annuum (the largest group, btw), C. baccatum, C. chinense, C. frutescens, and C. pubescens.
Caution: For practical purposes it was long thought that only Tabasco was a member of the frutescens species. Recent research indicates that there are no differences between the frutescens and the chinense, and it's now recommended that they all be grouped as C. frutescens. To be totally safe, if you plant Tabasco do not plant any of the C. chinense.
While isolation by distance is impractical in most home gardens, there are other methods if you do grow more than one of a species. Caging, for instance, is quite effective. So, too, is hand pollination. And you can often get away with closer distance if there are significant physical and attractant barriers between the two. But multi-species is really the safest way to go.
Of course, if you don't intend saving seed, none of this applies.