I will be shocked if a leak of this magnitude can't be located with UV dye.
I have a tracerline system. The light works great, but the dye application stuff was much less than impressive. Since it's 134, it's easy to get a can of UV dye and just charge with it. I saw a UV light at O'Reilly's the other day for $35 or so.
I got a system from the local auto a/c shop that had an injector that put in 1 oz. of oil with dye. It works great.
I would look for the leak and repair it, replacing all the parts you mentioned is most likely unnecessary if your compressor is running okay. Since it's 134 finding the leak should not be a ridiculously expensive or time consuming project. Regardless of what else you do, you MUST fix the leak so do that and then reevaluate.
Make sure you have a way to evacuate before charging.