Care is essentially the same. You still need a temp gradient, gutloaded insects, UVB, water etc
Veileds can bask in higher temps than panthers, and night temps can drop a bit further for veilds as well.
Egg production can be reduces and even haulted in Females veileds through diet and temp. I've not been able to achieve this with panthers and dont know anyone else who has, so you must be prepared to deal with eggs if getting a female (really you need to be prepared with a veiled too anyhow).
Panthers tend to be a little more expensive to buy up front. But its negligable compared to the other costs over time.
I hear about Veileds being agressive /territorial a little more than panthers (both easily can be though).
Go with the one you think looks best to you. BOTH are excellent animals to look at.