Hi

Yes you can re-pot now but give it a good soak first before you start.
I use a soil based compost John inns no 3 on bamboo/shrubs in pots plus the weight helps if its windy to keep it upright.

Multi purpose is cheaper to buy but runs out of food quickly and dries out quickly in the summer also holds too much water over the winter.

Hope that helps

Re. type of pot - try to avoid metal (gets too hot in summer) and square shape (rhizomes end up in the corners).

Also avoid pots that are narrower at the top than the middle as you have to break them to remove the plant when it needs repotting again.