The best bang for your buck would be a Merlin IIB. The IIB is somewhat of a slug with it's dash 1's, however it offers the biggest cabin by far as well as the operating efficiency of a turbine. If you're flying around the Texas area I would consider this. It's cheaper than the 421. Having flown both I can honestly say I prefer the MerlinIIB.As an old aircraft you will need to do a thorough prebuy ( I can recommend a service center in Texas if you pursue this) . If you would like to spend $400,000 or more then maybe a Merlin III would suit you fine, There is no comparison in performance between the IIB and the III. The Merlin III will fly circles around most of it's competitors while also being reliable and low cost to operate. I just thought you might want to consider these 2 also, as another option.