AC compressor lit up, AC questions

[shifty]

Reckon I need to fix this. I survived last summer but don't want to again. Know this - I'm not an AC guy.

Gist: 98 Sierra, L31 5.7, A/C is shot. I know it's a leak. Suspect It's the compressor.

Piped in one can of R134a. Worked great for an hour. Then dead. Piped in R134a with dye to check for leaks. 30 minutes later, dead. Busted out the light and I see the entire housing of the compressor is freckled like a Christmas tree, front of housing, back of housing, and a lot along one of the seams. See pics, best I can do with two hands, special light, phone with glasses over it.

Found the correct AC Delco compressor/clutch for $200 on sale. it looks like it's just a few bolts and bracket out to swap. Worth doing myself?

If yes, what else is necessary to replace, orifice tube and receiver/dryer?

Or just "take this one in to a reputable shop"?

(I have a Hayne's manual, if it matters. But didn't seem too helpful, only shows clutch replacement)

Figured I'd replace serpentine at same time. Truck is getting close to 90k miles and it's got the original belt. If I do it myself, I figure I can save a couple hundred.