I don't know about the selections that are available to you in Gnarnian stores, but you shouldn't have much of a problem finding something workable. MG is not the devil; contrary to what many would have you believe. It just requires a different [lazier] style of soil growing. However, if you have the option, FoxFarm makes some good stuff. I use Ocean Forest. Otherwise, especially if you are going to buy expensive liquid fertilizers, just go with something cheap and organic. If you have a good farm supply or similar, you can buy big bags of peat moss mixed with compost for half the prices of even MiracleGro.
If you do go with MG, just take it easy. The time release fertilizer in it will fuck your life up if you insist on adding [unneeded] nutrients. A lot of the MG woes I see on here are due to nothing more than people trying to force feed their plants Nitrogen when they don't need any more. This will not make a plant grow faster; it will burn it. See what you can get, and make it work for you.
S-Town