OP here... so I ended up getting the Arkel Tailrider. Looked up a local retailer and found a 10% discount on the normal price. Of course, I share the same sympathies of some here who think it's a tad on the pricier side, but after having looked and felt the bag, and with the lifetime, no receipt, transferrable warranty, I just felt I couldn't go wrong here.

Some pics of the new setup:



With the bag, I can fit two meals, padlock for locker, bike repair tools, lights, garage door opener, spare tube, and a spork lol.

Really looking forward to starting this full day setup on Monday, along with some meal prep to boot.

Thanks for all the help everyone