Femurs, especially with nails, are recognized for producing optimal outcomes in healing and height gains while reducing complication rates. The main downside is the expense, which is why I believe external techniques for tibias are available to provide a more affordable alternative, albeit with higher associated risks.
I strongly recommend opting for femur/nails if you can afford it without hesitation. However, if budget constraints are a concern, seek out a reputable doctor who can perform LON on tibias.