Looking to replace my Weil McClain QB-180 Burner

Hello, I have a Weil McClain Gold with QB-180 burner. I've lived in my house for the past few years with no issues. However, the past month my burner has gone out at least 20 times with my oil company coming out a dozen times to troubleshoot. They have replaced my motor, relay switch, and my fuel pump apparently 5 times. My Aquastat recently took a turn for the worst as well, so I will be replacing that soon. The latest attempt to fix my problem was by installing a TigerLoop, which to my eyes just looks like a small reservoir to feed fuel. Based upon my research and from information from my Uncle he has recommended I also go ahead and replace the QB-180, since they are prone to problems. I was looking into getting a Beckett, but they come in many different options and I'm not sure what model to look into. I've narrowed it down to an NX or AFII and I was also told to get a two stage pump. I have two zones and it provides my hot water. Does this seem like a sufficient replacement for my QB-180? Would that model be sufficient for what I'm looking to use it for? Also, I plan on searching, but how hard is a DIY job for replacing this? I've done electrical work in my house and worked on my car extensively (bleeding brakes, timing chains, car audio, etc..). I have no problems learning and researching beforehand, just wanted to see if this something I can tackle on my own. I have invested 500 (not counting the service contract) to my oil company so far with them just throwing parts at it. If I do indeed need a new burner...I'd rather do it myself and save money. Thanks.