I really liked kettlebell stuff; I wrestled for a year at a club in college and saw a lot of improvement from doing the basic swings, snatches, clean and press, and front squats.
More unusually, I had a lot of success with working with a sledgehammer or using a gada - a Hindu wrestling strength training thing, like a cement ball on a 4 foot pole you would swing behind you and explosively pull it in front of you; it as a movement is really similar to striking a tire with a sledge, but you can make a really heavy gada for really cheap compared to buying a heavy sledge. I liked it because you could load the movement really heavy, and treat it as a strength exercise. It made my shoulders, arms, and grip very strong.
Lastly, I really liked carrying a heavy sandbag slung over my shoulder for long distances, like a mile or two. I worked up to a 90-lb sandbag for 1 mile without putting the bag down; if I walked at a fast pace, I would be breathing really hard (was great for conditioning) and it made my core very strong and resilient. I love bridging movements, and this felt like a perfect way to develop strength both for that and for holding people down from top (something about the uneven loading of carrying the bag on one side felt like it transferred really well). I would squat with the bag periodically every time I walked, and picking the bag up and shifting from one shoulder to the other made me basically power clean the bag many times every time I carried it,
There's nothing wrong with just doing basic, heavy barbell stuff (and its probably better, lol), but I did nothing but sandbag carries and sledge stuff for about a year and built a lot of mat-usable strength; I didn't feel like I was missing anything, and all the sledgehammer stuff kept me able to do sets of 10-15 pull-ups without really ever doing them.
I also got to do all of my strength and conditioning stuff outside, which is something that always makes me feel good (sun, fresh air, etc).
Tom Lawlor - I can't express how awesome of an exercise the Turkish Getup is when it comes to grappling.
How do you program your Turkish Get Ups Tom?
I've seen some suggest multiple reps for the duration of a round i.e. constant get ups for 5 minutes, and I've seen some suggest low reps i.e. 3-5 with the heaviest weight possible.
I'd suggest avoiding machines whenever possible if there is a free weight version of the same exercise. That should help strengthen grips and the core.
Brings the hips and abs together; coupled with good technique and you'll be sweeping fools.
Weighted hip extensions. You'll be uppaing fools into the ceiling and your ass muscles will be the envy of all the older Brazilian black belts. Kettlebell swing off of two cinder blocks is also great - but theres no need to swing it above your chest.
Goblet squat: ass to grass range of motion great to flexibility and strength in the folded position.
Dips. Most closly mimicks much of the pushing being done when on the ground. . Bent over row: most closely mimicks the angles of pulling done while on the ground. Great with kettebells - youtube the renegade row as well which is as good as it gets..
Any heavy kettlbell lifting from the ground to overhead - whether the turkish getup or clean and press - all work great at building the hip extension and rotational strength(one kettlebell) needed for dealing with 150lb Brazilians when you have little technique... if you have good technique as well then great!