Indoor Housing ideas/help please

[Widgitwoo]

My housemates are moving out of my house so my tortoises are getting a new and larger indoor enclosure.
I have 2 torts both 6 years old, one spur thigh and 1 hermanns so I have a double decker enclosure. Think bunk bed style. Each of the current enclosures is 120 x 60cm. They both go out around the house during the day and in the garden in the summer.
Each of the new enclosures will be 240 x 100 cm.
To maximize space I am going to set them up in the same double decker style but I want ideas on what to put in the enclosure. Just want them to be happy and not bored or hungry when I'm not around to get them out.
Where the current enclosure is smaller its just got 1 heat/uvb lamp, shallow water bowl (I use a terracotta plant pot saucer) and a hide for them to go into if they want to. Neither of them really use the hide but its there if they to.
As this is going to be a bigger enclosure will I need a second heat lamp? Does it need to still be UVB or is just a normal heat lamp ok?
I was thinking of using growbag trays - the ones I have found will mean there will be 5 in each enclosure, I was thinking of making a couple of them into grass/dandelion trays so there is some different terrain and food source when they want it.
The spur thigh seems to really like climbing and exploring everything so I wanted to put a bit more stuff for her to interact with but I am worried about her ending up on her back or stuck.
Ideas or photos of your own set ups would be really helpful.
Thanks in advance