Allnic 1201 replacement tubes?

Hello all ...I have an Allnic 1201 phonostage and I think the Mullard E180CC’s are nearing the end . Should I pick up the same NOS Mullards are there alternatives where I won’t lose performance? 
Also they seem difficult to pull . Like they are loose at bottom and will just rip apart but I might be overthinking it..? Thanks 

VPI super prime scout 
tekton encore
manley snappers / jumbo shrimp