baflyrod: Some of the work you want to complete may require fitting of parts like the grip safety, or gunsmithing services like changing out the front sight and unless you are either really good at this sort of thing or a qualified gunsmith, you may wish to have it done for you and save yourself some serious aggravation (as I should have done any number of times......).
I think one of the best tools you willneed is right at your disposal - it's the internet and Greybeards. We can surely point you in the right direction to preferred gunshops/smiths. I would check with William Layton and see who he uses.
Re: your questions: Your pistol would take a grip safety for a Series 70 if using Colt parts. You can obtain a drop-in beavertail from Kings, and other places. Hammer and trigger groups often work better if they are made by the same parts maker or the same gunshop. For sights, I would use Heinies or something similar and even adjustable.
I am also going to recommend that you take this pistol to the range and shoot the snot out of it to see how she shoots and functions, and feels in your hand - you may change your mind on some of the 'modifications'. I would go one step further to recommend a shop/gunsmith that specializes in 38 Supers because my thoughts are that you could get the gun, shoot it for a while, save up your $ by not making any modifications yourself and then sending it out for the service you want.
And don't forget to have fun........or to let us know whatcha doin'.......
