Well you can get many options. Depends on your pricerange and what you are willing to sacrifice.
Cheaper (Meaning under $400) screens are not very easy to see in the sunlight. They get overpowered and then you cant see anything really. Transflective is the way to go there to get around this problem but you have to pay for it. The 8" transflective is $700 from the store.
Then there is how long you want it to last. Xenarc is regarded as a better brand and people assume they last longer. Lilliputs are more of the cheapest of the cheap but be prepared for random problems and a moderately speedy death.
I'll leave you with that.