To the above post, try feeding every 5-7 days. Every 9 or 10 days just isn't often enough, especially when feeding small hoppers. That's just not enough food and he/she isn't going to grow very well.

I have babies that are in the 70g range and they eat live, small adult mice(not fuzzies, not hoppers, not weaned mice, small adults). They take them down just fine and they are ready to eat again in 7 days. These babies hatched a little over a month ago and do well with this size meal.

Your snake is very capable of taking down the prey safely by himself, they have evolved over millions of years to be able to do this. Either a small adult mouse or a small rat pup would be fine. Just pre-scent the room for about 30 minutes prior(mouse in a cage beside the snake's enclosure so the snake knows what is going on and can prepare himself), then drop the mouse in on the opposite side of the enclosure as the snake(there's no need to move him for feeding, if you have been). Make as little movement as possible. It works well for me to make the room dark and just carry around a flashlight to see to feed everyone.

If he's been on mice, I'd stick with mice for a bit unless you can easily find same-size rat pups every week. I can get mice easier and they don't outgrow the sizes I need, so all of my Ball Pythons eat those(all 35+ of them).