sounds like you and your boyfriend just haven't found the right condoms for you yet
you're right: it's important that the condom rolls down completely. at the same time, it's important that the condom sits tight and close, without folds and air pockets between the condom and the skin.
the problem you two might have here, from what you wrote, could be that the ring of the condoms you're currently trying might be too tight. - that's a pretty common problem. i'd recommend that you simply try out a variety of brands of condoms. - there are both smaller (i.e. tighter), wider or shaped condoms around. - buy a variety of small packs until you've discovered some you like. should there be a condom shop near where you are, go there and see what they have.
my partner - who prefers wider rings, too- and i have found that aussie brand saturn's "larger fitting condoms" have a comfortable ring and roll down easily.
also, make sure you don't try to put the condom on until he has a full erection. - and also, lend him a hand. sometimes, especially if the penis in question is uncircmised, it migth seem like one needs three hands.
hope this helps.
Spike: (In response to being asked to fight a troll) "I would, but I'm paralyzed with not caring very much."