I've had some experience with modified "equipment" and being on a budget. Try to get your hands on some Coke/Pepsi plastic crates. I used to use 3-4 per side and tied them with rope, bungee cords, etc (for stability). I used to do dips quite well with them.
Squats are going to be trickier. The deadlift/split squat combo is definitely a good way to go. The split squats offer many ways to load weight. Heavy dumbells, weighted backpack, and even the weight that you clean up to your shoulders would be fairly heavy for split squats.