I have a Mini and have a Quinny Zapp. Very compact and lightweight but the downside is that it's prone to tipping (have had the car and the Zapp for about a year and DD now a sturdy but wriggly 2-year old!), but it was fine when she was smaller.
I had a 2nd hand (SIL's) travel system with DS and found it a complete faff to fold up etc, so mainly kept it fully assembled and went for walks from home rather than putting it in and out of the car. DS went into a basic Mothercare folding buggy from about 3 months.
Before we got the Mini, when I first had DD we DD got a Mothercare 'from birth' buggy. Still have it in our other car. I woudl recommend one of these as my preferred choice but I don't know if there are any 'compact' versions on the market.
Unless you're going to do a lot of travelling in the car with your 0-3 month old I really don't get the point of travel systems as I don't think you'll ever get the real moneysworth out of them (you can tell I'm from West Wales!). The cost of the Mothercare buggy and our Britax car seat (both bought on sales at Mothercare and ToysRus respectively) was about £100 which is loads cheaper than any travel system, and meant that I didn't feel bad about splashing £140 on the Zapp later on.
I don't know if you can get a travel system that works with the Zapp, but if you're still set on a travel system, I would get this as your DC can go into the Zapp itself at 3 or 4 months and you can still use the car seat until age 9 mo or whenever they grow out of it.
Sorry it's long but hope it helps!
Personally, found the whole 'huge choice' of pushchairs on the market very bewildering!