Scooters - any recommendations?

Hi there,
My 4.5 yr old and 3 yr old REALLY want scooters for xmas. I'm not sure what type to get (I've seen some that have 3 wheels - maybe for the younger son?)
Also, do some come with fatter wheels than others? Any brand names that you would recommend?
We live on acreage with NO concrete or sealed roads (yep, I think the scooters are going to live in our car for outings!).

Any suggestions would be appreciated.
TIA

The Micro brand are great. Particularly the Mini Micro for your 3 year old. It's got 2 wheels at the front and is a good first scooter. They are very well made. We have them at my toy library and with constant use they rarely have any problems. Cost is about $125 new.

dd has a mini micro, it is great but much better on hard surfaces than paddock.

Mini Micro for your 3 year old and Maxi Micro for 4 and 1/2 year old. Mini micro costs about $120 and the Maxi Micro about $179 but they are so so so worth it!!
We had a diff scooter but it was heavy and hard to use, boys kept playing on friends kids ones and all had the mini micros and loved them so I bit the bullet and bought them.

The mini micro is a fixed handle length where as Maxi Micro is adjustable but even at its lowest level its only 2cm higher than the micro. We have 1 of each for a 2 and 1/2 yr old and 4 year old.

Mini micros are fabulous. They are so good. Both my boys learned to ride at about age 2. Having the 2 wheels at the front makes a huge difference than two at the back - they don't get in the way of their foot/leg as they scoot. Ours has had thrashing and it's still going strong. You can get replacement parts, but we have not needed to yet.

Learning to lean in order to turn is a great skill. So much safer than turning a handle.

We do a bit of off road scooting, but it would be hard to learn that way.

we have 2 Maxi Micro as I felt that they were an investment that they would use now and grow into also.

DD1 got hers for her 3rd birthday and was competent on it from 3.5
DD2 snaffled her older sisters from 2 and then got her own and has owned it ever since.

I love them. I just took both girls on a long walk today with DD1 (4.8 yrs) scooting on her own and dd2 scooting some of the way and being pulled by my pram strap the rest without incident. They are so easy to ride, steer, stop etc.

FWIW, my 4 yo struggled on a 2 wheeler at a friends place recently and 2 yo struggled on a 3 wheeler (1 wheel at front, 2 at back) on the Micro scooters they are fine.

DD1 has got a Mini Micro too. She got it for her 3rd birthday a couple of weeks ago. She loves it and is already riding it well. They seem like a great brand and were recommended to us by several friends.

Bambini pronto have the big ones on sale - $165 and free express post. Not sure how long for, though.
I just bought two, but had to buy them separately as it's only free up to 5 kg

Thanks for all of the replies and recommendations! It looks like the mini and maxi micro are the way to go
Ta