Welcome to Airstream ownership. It's some work to renovate an older trailer, but the enjoyment you'll receive makes it all worth the hassle.
You asked if there were anything you might want to know before going with a compressor fridge.
A few items:
1) It may decrease the value if/when you ever decide to sell the trailer as it will no longer be self-contained. The caveat with this is: new solar technology may provide a way to go with a compressor fridge and still be self-contained, but that is a whole other can of worms you may or may not want to explore here on the forums. Others have invested the time, research, dollars and labor to make their campers virtually self contained on solar, which is pretty cool. Some also bring a generator along just in case. You can search the forums here for extensive threads on adding solar, should you be interested.
You may interested in knowing that AS has completely abandoned ammonia evaporated (propane-powered) fridges in their BaseCamp trailer (long story short; poor design of the trailer made ammonia fridges unworkable, so they went to compressor fridges, but now the BaseCamp must be plugged in for the fridge to work, or be relegated to being just an ice box)
2) So if you do put in compressor fridge with out any Solar/Battery to power it off-grid, and the power fails at your campsite, your fridge will only be able to be an ice-box until power is restored.
3) One cool thing about ammonia evaporated fridges is the ability to keep your food cool on long road trips and/or avoid having to stop at the nearest grocery at your campsite first to stock up on any cold food/beverages before arriving at your destination. The worry-free ability to cool things and keep them cool enroute can't be overrated. (There are workarounds to this with a compressor fridge: freeze everything a few days before departure, load it up, let it slowly defrost in fridge on way there) Ask yourself how wonderful and meaningful it is for you to, after a long day of (perhaps stressful) towing, to pull into your campsite and share a perfectly chilled beverage of your choice with your friends and loved-ones?
OK, so on the other side of the ledger is this:
- Compressor fridges are generally cheaper to buy and easier to install and fix than ammonia evaporated fridges.
- Compressor fridges are not as finicky; they don't have to be level to work right.
- Compressor fridges go from room temp to cool much faster than ammonia evaporated fridges and are, in fact, more energy efficient, if you measure the BTUs required.
- Some people may be uneasy about another propane source in their camper (besides your stove/oven)
- You prefer the look of a particular model.
Hope this helps. Remember, however, it's now your trailer, do with it what makes you happy, avoid doing or not doing what brings you regret.