alright, i've thought about it some more.
I'm going for a wilba design, with some minor alterations. which are mostly frontpanel related.
His design is very good, and combined with the ease of construction it makes it the better choice.
I've ordered the following from mouser:
4x 100K AUDIO POTMETERS (for the feeding the out back into the in of the SID)
Some screws, washers, and spacers.
100x 7.0 mm high 100gf buttons. which i will use with custom caps. (ordering a 100 is cheaper than ordering 50, weird)
1x pactec pt-10 production unit, which is only 14 euro! it doesnt have panels, but i dont need those!
this means i would only need a CS PCB from SmashTV (i haven't heard back yet, i'm guessing he is enjoying the holidays and has taken some time off.) which hopefully will fit inside an envelope and means cheaper shipping i hope.
and i would need a front/backpanel.
i have a preliminary design for the frontpanel and will be easy to get lasercut out of plastic. for the backpanel i couldnt find a DXF file, i've contacted wilba for a frontpanel file with mountingholes, so i can have the choice to mount the spacers without jbweld (afaik, we dont have that in holland). When i get a reply i'll ask him about a DXF file for the backpanel as well.
and finally a question. i'm going for the feedback option,
and im wondering if the [EXT IN] button near the filter is switching only the audio in, on or off. or is it doing something more?
If its only to switch external (or feebacked) audio on/off, i could rename it to feeback, change it in the software as well, would look nicer imho.