It is hoped models of three soldiers - each depicting one of the old regiments - will be cast in bronze and displayed at the Arboretum in Staffordshire.
The Devonshire and Dorset Regimental Association said a "substantial amount" of the Â£140,000 cost had been raised.
A fundraising appeal has now been launched to raise the remaining money.
Mike Richardson, of the Devonshire and Dorset Regimental Association, said the sculptures would also be a "salute" to the families of those people who served in the three disbanded regiments, "not only in the small operations during so-called peace time but in the two devastating world wars".
Paddy King-Fretts, who served in the 2nd Battalion Dorset Regiment, completing three tours in Northern Ireland, said the statues "mean a lot".
"I've been to the National Memorial Arboretum three times and the names of my soldiers that fell are engraved on the walls there, but it's nice to have something to compliment that and for the rest of the nation to see and ponder about," he said.
The sculptures will be created in Andover, Hampshire, before moving to the Arboretum in Alrewas - the UK's national site of remembrance.

The London trio are up for best UK act and best album, as well as getting two nominations in the best song category.
"We got told like this morning 'Oh I think you're nominated'", said Dappy.
"And I was like 'Oh yeah, which one?' And now we've got nominated for four awards. I mean, wow!"
Bandmate Fazer added: "We thought it's best of us to come down and mingle with everyone and say hello to the cameras. And now we find we've got four nominations."
The band have two shots at the best song prize, getting the nod for their Tynchy Stryder collaboration Number One, and single Strong Again.
Their album Uncle B will also go up against records by the likes of Beyonce and Kanye West.
N-Dubz picked up the best newcomer Mobo in 2007, but female member Tulisa said they wouldn't be too disappointed if they didn't win this time around.
"At the end of the day we're grateful to be where we are in our careers.
"If it don't happen then it don't happen - live to fight another day and keep on making albums and hits for the fans."
Dappy also revealed they could be performing live several times on the night.
The group will be doing Number One and also a possible rendition of the War Child single, I Got Soul.
The charity song is a  re-working of The Killers' All These Things That I've Done and is set to feature artists like Chipmunk, Ironik and Pixie Lott.
This year's Mobos will be held outside of London for the first time, in Glasgow on 30 September.
N-Dubz said they were looking forward to performing for their Scottish fans and boasted about their recent shows north of the border.
"We just done Edinburgh the other day," said Dappy.
"We smashed up an N-Dubz show over there. We done Aberdeen about three or four months ago - we smashed up that show over there! Everywhere we go we smash it up!"
Three statues honouring the Devonshire, Dorset and combined Devon and Dorset Army regiments are being planned for the National Memorial Arboretum.
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N-Dubz have told Newsbeat they are shocked to have picked up four nominations for the Mobo awards.