I need some advice please :)

If you want some smallish that's a decent tank/damage dealer, a Shadou Cub might be a good choice. It's a really rare pet though, but you seem to be doing ok with that (Windwalking piggy's a rare pet too).

Alternatively, the Guardian Wolfkin is pretty good when levelled up. Just remember to level up its main attack skill (Flesh Ream, IIRC) so it can hold aggro better. (If you still have your Sharptooth Wolfling, that's actually the best since most pets starting at lower levels gain better stat growth over time.)

Eldergoth Marksmen/Sharpshooters are basically variants of the same pet, but only with different skills/levels. Go with the one you like most I guess. Remember that you CAN level up pet skills at Mrs. Zoologist in Archosaur.

I'd say you could stick to the Wolfkin or Sharpshooter for luring, since one is fast and fairly durable (used in TTs for fast moving enemies), the other has a ranged attack (turn off skills so it uses its ranged attack to pull).

I'm personally using a Crystalline Golem (Slightly better stat growth than Volcanic Magmite AND you can still teach it Tough) and Frost Antelope (which is decent at 7.0m/s+ and can tank magic attacks well but physically weak as tissue), but only because I really don't have much inclination to change/level additional pets at my level. ><

You don't ask for much, do you? Guardian Wolf is the closest you'll ever get to near tank stats and the ability to pull in one pet, tho it will do nowhere near good damage. Shadou Cub is a great tank but it's damage is also low and it is too slow for pulling. The closest pet i can think of to what you seem to be looking for is the Cuddly Pup. It is a lvl 40 rare and while far from a tank, it does have overall decent stats, certainly small, it is amongst the fastest pets and does deal decent damage. You shouldn't have much need for a tank already having a magmite anyway. You should consider that Eldergoths are usually considered pullers (because of their ranged attacks) so it might be redundant to have two pets filling the same role. I imagine that by "move set" you mean their skills in which case simply choose the one you like the best. Although usually the lowest level in a family has the best stats, and is thus the recomended choice, very few venos do actually take Eldergoths into high levels so it shouldn't make much of a diference. Just remember to turn off it's main skill to use ranged attacks, tho i should note that the warrior is actually only capable of using melee range. Hope this is useful.

I always thought that my golem is fast enough for pulling
but on the few times where the mob is too fast, I use the scorpion.

but for that small luring pet, I would suggest the frogling instead
its faster than the cub, has good p.def and excellent m.def
the market price is cheaper too