My two cents
I replaced the bracket on my Oday 23; conceptually, it should be easy. Just unbolt the thing and rebolt the new one. However, there were complications. The spacer block (that angled hunk of fiberglass) was rotting away inside. I had to scoop out all of the rotting wood and beef it up with West System resin. It was the first time I worked with fiberglass and it was kind of fun. I also replaced the nuts and bolts. Finding stainless bolts that were long enough was a bit of a chore. I wound up making them myself from threaded stock; turns out they are available as a special order item from West Marine. Oh well. I also discovered the joy of using copper anti-seizing goop; spread this stuff on the end of the bolt before putting the nut on, and you will always be able to unfasten the nut. No corrosion! Definitely was easier to do this project over the winter. I took the whole thing apart after the boat was out of the water, and took the spacer block, bracket, etc. home with me.As a general matter, try and find a replacement bracket that fits the existing bolt pattern of your spacer block and your transom. Otherwise, you could be stuck making a new spacer block and drilling new holes in your boat. Rudy at D&R Marine knew exactly what would fit and sold me a new bracket. For me, this was the biggest reason not to go with a four stroke engine; I didn't want the hassle of either. All of the four stroke brackets I have seen have a wider base and wider bolt spacing than my "standard" two stroke bracket.Will your two stroke bracket be overwhelmed by your four stroke engine? Probably not. Each of us has a different level of risk acceptance and only you can answer if you will be comfortable taking that chance. If the engine does overpower the bracket, I think the most likely result will be that it bends, not breaks. If you are ok with the risk, you might want to at least go with a new two stroke bracket.The five hp four stroke should easily drive the 22 at hull speed. I have an eight hp on my 23, and it is more than enough. btw, if the engine comes in an "extra long shaft" model, go for it. Even with the 20" long shaft, the prop will come out of the water easily. The 25" extra longs are definitely worth the money. I also have electric start; well worth the money in my (and the Admiral's) book. However, I seem to recall that it didn't come on anything smaller than the 8 hp a few years ago. If that's the case, it's another one of those choices for you. Starting a small outboard by hand is no big deal, but electric start is one of those things like air conditioning: once you have it, it's hard to do without. Electric tilt? Don't have it. I don't bother raising or lowering the bracket itself. Its way too difficult. I just tilt the engine out of the water. I don't know how big a unit it would take to do the tilt electrically, but it sounds like a nice upgrade. However, with only a 60 lb. engine, it also sounds unecessary.