Bit difficult to make suggestions without knowing you terrain , tree size, cost structure etc. Generally go for the brand that will give you the best service in your area. (Satco 420 felling head loading) I guess you know about the satco 630E felling head so the operator can change quickly between felling and processing. (Tigercat 855D with Tiger cat 5195 felling head )
Discuss this in the forum topic Directional Felling Grapple.