Tethering implies using an Android phone
I have an ancient (E63) Nokia
Mrs has a 2 year old Blackberry
Neither are good starting points for tethering.
Not quite true, some Window mobile phones such as the Nokia Lumia allow tethering.
In fact I think that the Nokia E63 as well as quite a few other later high end Symbian based phones can be used for internet tethering, there are/were apps for turning the later Nokia Symbian phones into wifi hotspots e.g. JoikuSpot
Looks like you are correct about the E63 ie a bit of a Google says that using Nokia Suite and a connector cable I should be able to connect the E63 to a PC and send messages via the phone. I have had a try - and failed miserably, but early days yet.
ANYWAY - I think I have decided
Option 1 is to get the Mrs Blackberry 9300 unlocked and then she can use a local South American SIM card. Only issue is that strictly the phone is locked to Virgin until end Feb - but maybe is I beg they will let me have it unlocked by mid Feb
Option 2 is to buy outright a new SIM free Motorola Moto G and again a local South American SIM card can go in that.
Looks to be a good phone for the £130 - or a bit more for 16Gig. No micro sd slot but I can cope.
Snod