I use a shurflo 5 lpm pump with one of crow electros ( now spring ) original mk 1 analogue controllers, basically just a dial and an led !
Has never given me an issue ever !
They don't make those controllers any more ( shame ! ) but I never got on with the more advanced digital ones, constantly fiddling with the calibration and de etc.
My advice would be to consider a basic motor speed contoller such as ebay and maplins sell, there are even some specific wfp ready models on ebay but cannot vouch for how good they are .
But I really think it pays to keep things simple.
The shurflo pumps are excellent and will last years, the only thing that may fail on them are the pressure switches, but then that goes for any pump and they are cheaply replaced in maplins for a few quid.
The only thing I'd do different if I needed to buy another is probably go for the 7 lpm one. The added flow could be useful on some jobs and if using with a controller you could always turn it down anyway.