I am sorry to say no matter what cams you put in you will need to re shim , the SE engine has solid lifters and so even if you put a cam in out of a 2 litre then you would probably find that most if not all would need a reshim , also if you put a cam in out of another engine size then you will probably need to play with its timing to get any meaningful gains so it will need vernier pulleys fitted to allow this .

I have to say if you want to have gains then you might be disappointed as the only real way is to use components designed for the job , you say that kent / piper are expensive but they are due to the development costs to make sure they give a gain rather than giving nothing .

I would say save up and use the right components and you will be so much happier with the results .