It seems like you are trying to avoid having to invest time in understanding how to do this the right way in order to build a safe and effective heating system and/or spending the money on a prebuilt kit. You really have to pick one or the other: invest the time to save some money (noting that even this will be more expensive than you think) or invest the money so you don't have to build it yourself.
Electric heating elements of the size and power required for brewing requires relatively high powered elements and electrical equipment. Best case scenario, you have underpowered devices, and/or you break a lot of stuff. Worst case scenario: you can kill your self.
There is a lot of knowledge on the interwebs out there about electric brewing. Start with theelectricbrewery.com, then build from there.