DIY. It isn't that hard.

Sending it to a professional wouldn't guarantee you that it will be problem free and 100% zero leaks throughout its lifespan. Plus I've said it before that you have to maintain it ever so often like every 6 months to a year. Disassemble everything, clean the internals if got gunk, dust the radiator and reassemble everything to its working order. It doesn't mean that a pro install for you and you can use it for 5 years and not do anything about it.

Cyntrix would be the easiest if you want to use the RASA kit. Jibek and ezzy got a lot more choices in terms of individual parts. WC is not that hard even for a starter and as long as you do a preliminary leak test before putting in your motherboard etc, you're good to go.