Billy bookcase is a good upgrade from Detolf if you have been collecting for some time, it's sturdier, and the wood gives it a more classy appearance in my opinion. Of course, it's slightly more expensive than Detolf, but the quality is way better than Detolf too.

P.S For minion, I can't even think of any shelf suitable for it. Assuming TS is planning to collect stuff with more or less equal height to minion.