1. Light transport bot
The little brother of the Sequer. Could only hold 40u, but is much much faster. Ideal for getting a place quickly, or a small load on / off beta. ~100-120 KPH top speed with T4 LWF. Would have ~100-120 Detection, 80-100 masking. I think it should be 120/120 personally, would work both as a good beginner hauling bot, lightweight transport, and a good choice for ninja ops on beta.

2. Mech transport bot
Bigger brother of the sequer, younger of the Lithus. Holds 120-160u, the natural step between the sequer and the lithus. Slower than sequer, faster than lithus. ~80-120 detection, 80 masking.

3. Cargo Access Module
A module that allows you to set a password on your cargo hold, allowing players to open it like a field container. This would be great for harvesting among other things. While the module is active, people can access your hold with a password. Can be deactivated (closed). Needs to take up quite a bit of reactor/cpu so people cannot exploit this during PvP, and is ideal for fitting on transport bots. Also would add a decent amount of weight to the bot slowing it down.

T2 would be lighter, less fitting.
T3 50% increased range to drop stuff in / take out
T4 100% increased range to drop stuff in / take out

Thanks to CIR Tweaker for the idea on T3/T4 range bonus