[Arcmage]

Really confused which one to buy. 
Here are the specifications : 
>Pioneer SE MJ51 :                                                            

·         Max input power:  1 000 mW                                                   

·         Frequency response: 8 Hz to 25 000Hz

·         Impedance: 32 Ohms

·         Sensitivity: 105 dB

·         Drivers units: diam 40mm

·         Cord: 1.2m

·         Plug: 3.5 mm diam. 3P mini-plug (gold plated)

>Pioneer SE MJ151 : 

1. Model: Encapsulated type dynamic
2. Reproduction bandwidth: 10Hz~25,000Hz
3. Impedance: 32Ω
4. Maximum input (JEITA): 1000mW
5. Output sound pressure level: 100dB
6. Caliber of use unit: φ40mm
7. Plug: φ3.5mm stereo mini-plug (gold plate)
8. Code length: 1.2m
9. Mass: 135g

Which one will be best for retro styled music ? (ABBA, Boney M, Bee Gees, Gordon Lightfoot, Kraftwerk etc...)

And do you guys have any other suggestions of Headphones that is around $20-$30 (or possibly cheaper than that) and also good for retro music ?