I have a GORUCK bag and a 30 lb weighted ruck plate from them and have been using that for the walks. Seems to work fine. Get a huge pump in the rhomboid/lower trap area too.
I don't mean to piggyback question on this thread, but I had a similar question.
The 1.2 program calls for the "light" days for each lift to go up from the 5x5 from 1.1 to 7x5 (or 7x3 for the deadlift) at the same 75%, even though the weights are going to go up because the TM maxes go up.
I'm not at all challenging this, I was just curious as to why both the volume and weight goes up in this phase of the program?