While I'm not a 'smith, nor do I play one anywhere, I worked for almost 25 yrs in industrial machine repair and I've tinkered with enough guns over the years to form some pretty definite opinions about when to DIY. Most came from experiences, both good and awful.
There's nearly always more to a successful barrel swap on a revolver than just screwing the old one off and the new one in. The front sight might not line-up squarely, the bbl/cyl gap may require adjustment, headspace may be changed, plus it's all-to-easy to irreparably damage your frame and/or barrel unless you use a couple of special tools and a very good vise mounted on a solid, heavy bench.
Unless you're prepared to do some skilled handfitting or machine work to deal with it, I'd highly recommend having a pistolsmith do the job. Believe me, it's always cheaper to pay to have it done right than it is to fix a botch-up.
The grip swap and new sights should be no problem, as they're usually pretty much a drop-in proposition and are easily handled with common hand tools and a bit of care. I like the Millett sights. Mostly because they've solid and repeatable adjustments, are relatively inexpensive and readily available. They're a drop on fit and quite precise. The only hitch is that they have a funky adjustment screwhead set-up which need a special bit. A pocket-sized tool to do it comes with them, but it can be frustrating if you need to make a change and don't have it on you. There are other options, of course, but usually for about fifty to one hundred percent more money.
The only thing I can tell you that I've learned for sure is that if you'd rather not deal with Mr. Murphy, don't dive into anything that's almost sure to invite him over. Especially where a complex and expensive machine is involved. Either get the full skinny on what tools and skills the job needs to be done properly and acquire them, or send it to someone who already has them.
Special tool cost money. Usually a lot more than you'd save on a one-time DIY. And it's almost always a whole heckuva lot cheaper and less painful to hire skill and experience than it is to get it for yourself.
YMMV, but sending it out would save you a world of potentially bad Juju, IMO.
