I think folks here will need a lot more info before offering specific advice.. Such as - What varieties did you grow last year and what aspects of growing them didn’t meet your expectations? Disease, low yields, poor taste etc. How far apart are you planning to grow them in the bed, what will the bed be filled with? What kind of fertilization and pest control do you practice? If you can provide some details about your situation you will be more likely to get better answers.

As noted, it would be more constructive to understand *why* your tomatoes didn't do well. Otherwise any advice would be like shooting without a target. What exactly do you mean by "didn't do well"? If everyone you've spoken to and communicated with online had the same problems, we sure aren't going to fix that here.

Agree with the others that there could be any number of reasons for why your plants "didn't do all that well" so much more info is needed.

But neither planting fewer seeds of several types of tomatoes or more seeds of just 2 types can assure you better production. Variety and/or type doesn't make all that much difference as all will work fine IF they are given proper growing conditions - good well draining soil, no over-crowding, proper levels of nutrients provided throughout the season, proper watering techniques, sufficient sun exposure, proper planting times, support methods used, pest and disease monitoring routine, etc.

So those growing conditions are what you need to define here and work to improve. For example, what exactly did the local extension tell you?

Dave

tomatoes are self-pollinating, so it doesn't matter what type you grow.

Two things to consider are that the bed receives lots of sun and that they get nutrients.

Amending the soil with aged manure is always a good idea. Adding compost and fertilizer when planting is great, and many people add more ferts when the plants begin to flower.

Linda

I should add that there are a lot of people here who, supplied with a good description of your growing strategy and problems, could make suggestions for fixing those problems. But if we don't really know what the problems were, there isn't a lot we can say. We could be talking about disease, soil nutrient deficiencies, or lack of lighting, and there isn't one magic fix that's going to deal with all of them.

What are the breeds of tomatoes you're considering in both cases?