First, why are you specifically thinking of SSD drives and not the old spinners?

If you're thinking portable because you're going to carry them around a lot, SSD is probably good because the spinners can be damaged by shock if you drop them. Spinners are cheaper so you can get larger ones or more for duplication (field backup).

I don't do a lot of field work any more so I use spinners and find them quite reliable. Since I don't use many SSDs (except the ones that are built into my machines) I can't offer advice on specific brands/models.