Cart for Michell TecnoDec - Advice Needed ASAP

As part of a package deal, I've been offered the following carts at a reduced price:
- Goldring 1012GX
- Rega Elys

Would any other cartridge, similarly priced, work better with my system? I'm most concerned with achieving a balanced sound - think system synergy. Here is the associated equipment:
- Michell TecnoDec w/ RB 250 Special
- Pro-Ject Tube Box II/Encosse Interconnects
- Naim Nait 5i/CD5i
- Harbeth P3ESR

Thanks!