I wouldn't get a stainless screw kit as they are too soft, i.e. low tensile strength. Stainless stell fasteners are ok for rust prevention but stretch too easy leaving things loose and can round out the hex where you put the Allen key or driver.
Class A2 stainless steel is really soft, A4 is the highest and then only equivalent to normal class 8.8 fasteners. Capscrews should be high tensile, 10.9 as a minimum or ideally 12.9.
If you list down what sizes you need you can get high high tensile caps crews and stainless if you want from
www.modelfixings.co.uk
This might actually work out cheaper than a specific kit, you can get the screws that you need/want and also get replacements as and when.
Just a thought.