engine swap

right at the min im runnin a 1100cc but am thinkni about swapin to a bigger ewngine as the 1100 somewhat lacks in power  

im just wounderin what engines i have to choose from without spendin thousends

iv been told i could go for a 1800cc carb enghine out of a citi or the gti is always an option but obviosuly i will neeed brakes etc so would that prove to be exspensive and difficult ? also is the shell and set up the same in the 1100 as the gti (engine mounts etc ? )


thanks