Timber cladding for gate

[Arrowman]

I am looking to get an automatic sliding gate made up for the entrance to my house.
I have a guy in mind to made a box iron frame and he will install the runners and switchgear etc to run the gate.
But I wanted to clad the gate with timber.
Thinking of using lining the boards up horizontally and using different width boards with a shadow gap (I think I have the right term there) between them.
The two timber options I have looked at are cedar and Siberian larch but I'm open to other suggestions.
My impressions of these are - cedar looks well, is light but might damage easily
The Siberian larch is lighter in colour, is more hard-wearing but is inclined to be a bit more knotty.
I'd be interested in getting your opinions. Has anybody used these timbers on gates? How are they looking after a number of years? what annual treatment do you give the timber?
The lad making the gate frame doesn't "do" wood and is nervous about the wood twisting and weathering and looking terrible. I am starting to get worried too as this gate will be a feature at my house entrance so I don't want it to look a mess or require constant maintenance.
Many Thanks in advance

 

[nev]

If its of any help. This is my neighbour's gate. Cedar I believe, approximately 18 months old.
A few shakes appeared after a few weeks weathering and look worse when wet. It is untreated.
It has greyed much like old oak.
Made by Tumble Forge in SA 14.

BTW these pics were taken between light showers.

 

[AJB Temple]

I made my large electric drive gates out of Iroko. It weathers much better than the cedar in the pictures above and tends to retain its colour. They are pressure washed every two years and oiled. Good as new.

 

[Trevanion]

Can’t go wrong with Iroko with Sikkens on top.

 

[Arrowman]

Thanks for all the comments and advice.

I have seen a gate clad with cedar and its very like the pictures - a bit dirty looking but I noice that it has improved a bit with age and weathering.
I would like to consider Iroko but I think the price might scare me a bit - the gate is in one section (it will slide to one side) and is 5.9 M wide and probably 1.6 M high
I like the look of horizontal boards with variable widths - similar to this one

but I am unsure whether this arrangement will give a greater chance of the board twisting or perhaps popping the fixings off the steel frame.

 

[AJB Temple]

I would say you've got no chance of finding 6 metre straight boards. So a horizontal layout with joints will be similar to a floor. Are you sure that is the look you want?

 

[Trevanion]

I would like to consider Iroko but I think the price might scare me a bit

Cedar tends to be more expensive than Iroko more often than not.

The only thing you might struggle with is the 6m lengths as AJB said, and even if you could find 6m lengths it would be very unlikely to get straight ones.

 

[Arrowman]

I would prefer not to have joints in it - but i get what you are saying about the availability of boards that length that are straight.
Whatever about not wanting the timber to warp or cup when its on the gate i definitely don't want to put on twisted boards!!
I might have to rethink the layout so - maybe going vertical is safer

Any idea what thickness of board to use and what the cost to clad a gate that size in iroko might be?