I think it's down to personal choice re gel v patches.
I've always used gel as it's what my consultant suggested first and I've been very happy with it. (There are 2 types- Oestrogel and Sandrena.) I'd suggest Oestrogel as Sandrena evidently takes longer to dry.
Patches- some women like them but I simply didn't want the sight or feel of a patch stuck on my bum or have issues with them sticking.
The other bonus of gel - and it's a main one- is you can adjust the dose yourself, so although the starting dose is 2 pumps, you can start with 1, and go up to 4 (to get symptom control.) You don't need to see your dr to increase unless they tell you to stick to a low dose for some reason.
There aren't many choices GPs can give you with the progesterone- if you want body identical it is micronised progesterone. This is a capsule. You swallow it but in Europe many women insert it vaginally to avoid some of the side effects. It's not licensed in the UK for vaginal use for HRT for some weird reason, but- who's going to know :) ?
I doubt your GP will allow you to have a 3-month cycle on this.
The usual regime is monthly.
The only people I know who are on a long cycle are - by and large- doing it through a consultant, privately, because if there are any issues with odd bleeding (which can sometimes happen on long cycle) the consultant can refer them for a scan (privately and the cost is anywhere from £100 to £350 depending on who does it and where.)
There is a slight risk of endometrial thickening with long cycle which is why your GP is unlikely to a) even know about long cycles and b) will not in theory prescribe it like that.
You could- and this is not advice from me- stretch your cycle to maybe 5 weeks or 6 weeks, if they approve, once you've been using it for a while.
My own experience is I was on a 3-month cycle for some years. I did get some break through spotting and had scans- not sure if it was the HRT or late periods.
I now use a 6-8 week cycle but that is privately.
Hope this answers your questions! :)