SerpentCT4S,
If you used the TRF M chassis shocks PNo 54000, then they are shorter than the regular TRF shocks. A selection of springs would also assist with fine tuning later.
The aluminum hexes are not really necessary, however you can get them in 5mm and 6mm widths which can change the width of the car.
If you read the article about setting up a mini on the web site, it will give you all the info you need.
Regards,
Calvin.