I have been using a golite poncho tarp and equinox bivy combo for about six months now, I have used them in temperatures ranging from 60 degrees to 10. I personaly like a lean to formation more than the A frame in my oware cat tarp because it is easier to get into and out of, but if I expect colder weather or heavy rain I will set up my tarp in an A frame, for heat retention an more rain protection. As for the equinox bivy, I like it for the fall and winter, but in the summer, without bug netting it is horible, I woke up on several occations finding bugs and spiders in my hood, I am going to replace it with a bug net and ground cloth for three season, this set up has more ventillatin and is lighter too but will bring the bivy in the winter, but of course with the BMW bivy you dont have this problem. Also I am moving twords UL hammock camping leaving my 3.5lb load behind for a 5. But with a diagonal ridgeline, my poncho has enough coverage and only needs two stakes. You may consider buying a travel hammock or making a silk hammock, that is my next project after recently modifying my eagles nest to reduce the weight by 50%, even when hammock camping I am weight obsessive :-)
I dont know if I gave any real advice, but I do recomend getting either a poncho tarp or flat tarp, they are more versatile to set up and can be easier to get into your sleeping bag if set up in a lean to
here are a few of my favorite set ups
one of my golite poncho tarp and the other of RJs tarp, but I use it most often when tarp camping, it may be my favorite pitch
I like the first set up becaue it only needs one guy line, and I have even been able to angle the trekking pole in such a way where no guy lines were needed. who else has ever heard of a guy line less tarp?
I usually bring two 8 foot guy lines, so I can set up the two above set ups, a traditonal lean to, or if needed, an A frame with the sides staked to the ground