You have a lot of options here. I agree that you should get 1 more of the A4 and especially the I1. With the A4 it may not be necessary, depending on the overall stack plan.
You could even stack all of the mentioned products and there wouldn't really be overlapping issues and they would all add to eachothers effects. In practice it would be difficult to find enough skin space, unless applying multiple times a day.
For fat loss the U11 would help the most. UH would be a nice addition to cutting cycle, but in fairness UH is a nice addition to any run with the energy, mood and strenght increase. I1 is by far the most anabolic and would help with maintaining muscle the most and could even allow you to grow some lean mass, while on a deficit. A4 is a great test base -product, but I wouldn't personally use it, unless running the I1 or experiencing low T/E sides.
U11: lowers cortisol, sheds fat, helps in sparing muscle, farely mild on sides and easy to recover from.
I1: most anabolic, most suppressive, some users report lethargy, for some users the DHEA in I1 is not enough for a base and for them the addition of A4 will come in handy.
A4: best base for anything, may not be needed with the other products here, other than the I1. I would call suppressive.
UH: very versatile and a nice addition to any cycle. Energy, mood, strenght, libido and hardness, if lean enough to notice. Farely mild on sides and easy to recover from.
You could do a cutting cycle now with U11 + UH. And later on do a (lean) bulking cycle with I1 + A4.
Or if you bathe in TD's like @thebigt you can stack all of them and go for recomp or lean bulk or aggressive cut while maintaining lean mass.
The stacking options are pretty much endless, lol.