Seagull makes Xenon under cabinet lighting that needs remote transformers and also ones that do not. It is usually easier to conceal transformers in lower cabinets where there may be more room (not behind drawers). To run wiring in the walls it must be UL listed for that. Junction boxes are required for all splices because the remote transformer Seagull product is not class 2.

You can dim either type with the correct dimmer. Use magnetic low voltage rated dimmer for magnetic transformer and electronic low voltage rated dimmer for electronic transformer.