Hi sucramuk - I hope you have a fantastic trip to the north of KNP. It is truly magical up there - especially if you like birds and trees - some special ones up there.
I don't know Makhado but if there is a shopping mall there, you should be OK. Otherwise, there are several large shopping malls in and on the outskirts of Polokwane. After you leave either of those large towns, the area between them and Pafuri or Punda Maria is extremely rural with very few shops, fuel stations etc. The shops that are there are very basic, so you would be advised to shop in one of the larger towns - Makhado or Polokwane.
As for accommodation outside KNP in the north of Limpopo province, you should Google for bed and breakfast places and see what comes up. There are also some web pages that cover that sort of thing.
You don't say where you are coming from and why you need to shop that close to KNP. When we go to KNP from our home near Johannesburg, we do all the shopping and packing well before we leave and have a fairly straightforward trip to the park. I guess you are maybe coming from overseas and are flying in, so don't have the luxury of car fridges and freezers. Maybe when you do shop you should look at buying a cheap cooler bag and some ice blocks that you can freeze when you are in camp - makes keeping food fresh much easier.
Have a great time planning and have a super trip when you get here.
Punda Maria 7, 8, 9 Oct. '13
Letaba 10,11 Oct. '13
Satara 12, 13, 14 Oct. '13
Mokala, Karoo, Camdeboo, Addo Mtn Zebra 2 - 16 Nov. '13