I used the OMM "map case". The actual map case part is useless, you need a separate map case to keep your maps dry. I knew this though and used OS 1:25k maps which i scanned and printed onto A4 waterproof paper, and carried in an A4 Ortlieb case, rolled up and slotted in the fold the OMM map case makes. This worked well. The size of the bag was ideal for me as all i had in there was nav stuff, a bit of food and spare gloves. The fixing was interesting and i trialled several methods. I finished off with not using the bottom hooks and just threaded it on the waistband of my pack, with the top hooks clipping into a couple of split rings i attached to my shoulder straps.
Ribz, I searched and tried most and found this the most comfortable, versatile, less bounce, hard wearing, good storage, A bit of a faff when taking off and putting on , particularly if you aren't careful but a small price to pay imo. Well worth a look
Other option is an Aarn pack which has front pockets as standard but I didn't like it a much. But if it's very cold maybe better as bottles can be inside the pockets and protected from the elements more.
I've used (1) OMM Trio - very basic, attachments onto your sack are fiddly, map bit is completely useless (2) Inov8 - no longer available, well designed and integrated well with their old 25 (red) and 32 (blue) litre packs (also no longer available!) (3) Raidlight - large capacity, bottle holders, good fitting system. This is what I used this year and like it a lot.
I used the Ribz front pouches. Absolutely love them ! Great capacity, sit well, comfortable. Aside from my snow shoes (which I haven't had the chance to 'use in anger' ) This most exciting useful piece of kit I got new. Not cheap - but well worth it !
So are these front packs attachable only to the same branded backpack?
The Ribz front pouches are entirely separate but well designed so don't get in the way of main back pack