I can't recommend a CO2 system, they cost money to operate, plus you have waste, and the CO2 air leaks out a lot faster which means when you get home you have to drain the air out of the tube and refill...that's a waste of time to me. If I was racing then I would go with CO2 otherwise forget it. Besides why carry around unnecessary weight of the CO2 plus extra carts plus a backup pump? Really?? I guess if you are really hooked on the CO2 thing then why not just buy a hybrid pump? A hybrid pump is both a CO2 inflator and a pump, like the Birzman Infinite or the Lezyne Pressure Drive CFH, then at least your not taking up as much space.
Mini pumps you have to be careful buying because MOST cannot reach even 70 psi which most people run around 100, so what good is a pump if it can't get to 100 or so? there are only a few pumps that can reach 100, the first one is the Lezyne Road Drive large, Lezyne makes 3 sizes in that model, the smaller sizes will not make it to 100 psi, the large one does. If you want a really lightweight pump the Lezyne Carbon Drive will reach 100, that pump I have not used but people I spoke to that had that pump all said it does. Others that will reach 100 psi are the Topeak RaceRocket HP, supposedly the SKS Spaero SPort ALU according to what I've read will reach over 100 psi as well but I question it's durability since they seem to be spotty (I had a SKS Puro that was a piece of crap but the SKS Raceday Carbon was great, so not sure about this one). The last one which I haven't used but heard it works really well is the high end but heavy Silca Tattico; but I think with all the lower price options out there I can't really see the need to spend for Silca. There may be a couple of other pumps I missed that can reach those higher limits but the vast majority of pumps on the market cannot despite their claims of saying they can reach 110 or 160, they won't.