That's a nice idea! You can take this advice or leave it, but from experience as a tattoo artist (doing many, many coverups and such), it would be best not to get names. Instead, get a tattoo of something that
symbolizes your marriage. It's more unique, takes more thought to design, and you're less likely to regret it later. A lot of tattoo artists regard name tattoos as plain bad luck.
That was really smart. Prison tatts are notoriously aweful. Sure, I've seen some decent prison tatts, but I've seen a lot more that were terrible. Plus, there's really no way to make a prison a sterile environment, so the health risks are much, much higher.
Many people do not consider tattooing their bodies as being disrespectful. It's like a decoration. Temples are full of decorations.