I have an older marquis 7000 in my 94 Bounder, it has a ton of issues and was quoted ~1400 to fix it. Question is i found a local shop having a newer model marquis gold 5500 for sale for $500. How terrible of an idea is it to go that direction? My coach only allows me to run one A/C at a time as it is, so I don't see that being a huge issue. Would it even fit?