doesn't look hard to do, especially if you find an '83-84 celica with analog EFI.  much simpler than later versions.  individual components are expensive, but usually can be had cheaply in a package deal

i have a weber 32/36 on my 20R.  it actually has a smaller CFM rating than a 22R carb, but much higher than a 20R carb.  knowing this, i think it would be a better idea to use a weber 38 on a 22R application.  i don't have any complaints from my carb(other than it's a manual choke ), but it would be nicer if the rest of my engine was in good shape